This present invention relates generally to manufacturing objects. More particularly, the invention provides a method and system for wafer level flip chip packaging of micro-mirror devices. Embodiments of the present invention provide for chip-on-board packaging of micro-mirror devices in a hermetically sealed package. Merely by way of example, the invention has been applied to a micro-mirror array in a hermetically sealed package with a transparent glass cover. The method and structure can be applied to other display technology as well as, for example, charge coupled display camera arrays, and infrared arrays.
The packaging of silicon integrated circuits has reached a high level of maturity. However, conventional packages in which an integrated circuit device is encapsulated in a plastic encapsulant present several drawbacks in applications that require more than electrical operation of the silicon integrated circuit. An example of such an application is optical illumination and reflection off an array of micro-mirrors or other micro-electromechanical systems (MEMS) structure. For example, these applications typically require the ability to illuminate the top of the silicon integrated circuit with optical energy and subsequently reflect the optical energy off the top of the silicon integrated circuit with high efficiency. The optical properties of plastic encapsulants utilized in conventional packages, including lack of transparency, non-uniformity of the index of refraction, and surface roughness make these packages unsuitable for this application.
Additionally, many MEMS often require an open space above the surface of the silicon integrated circuit to enable the micro-electro-mechanical structures to move in the direction parallel to the plane of the MEMS as well as in the direction perpendicular to the plane of the MEMS. The physical contact that the plastic encapsulant typically makes with the surface of the integrated circuit, therefore, make this package unsuitable for many MEMS applications. Thus, there is a need in the art for improved methods and systems for packaging of MEMS devices.